phone number formatting

So all my customers are in the USA, and I’d like them to be able to put in their phone numbers in the format 999-999-9999 (as apposed to (999)999-9999 or worse yet 9999999999). So all they do is type in the numbers, but it shows and stores it in that format. Is there any way to do that? Maybe with js like ‘jquery.maskedinput.js’, or some other way? Anyone with ideas on how I can accomplish this?